• 1 M Na₂SO₄

Aqueous, 0.2 M samples of barium nitrate, copper nitrate, ferric nitrate, lead (ii) nitrate, manganese nitrate, nickel nitrate, silver nitrate, and aluminum nitrate were gathered, along with a dropper bottle full of 1.0 M sodium sulfate (Na₂SO₄). A few drops of each cation solution was placed into its own test tube, along with five drops of the Na₂SO₄. Silver nitrate, copper nitrate, ferric nitrate, manganese nitrate, aluminum nitrate, and nickel nitrate did not react with Na₂SO₄. However, Barium nitrate reacted with Na₂SO₄ to create a milky white solution, and lead (ii) nitrate reacted to create a gelatinous, milky white solution. The net ionic equations representing each reaction go as follows, in order:

Table 3a. Summary of what happened after 5 drops of 1.0 M Na₂SO₄ were added to each cation.

From there, 1 drop of 6 M Nitric Acid (HNO₃) was added to both the barium sulfate (BaSO₄) and lead sulfate (PbSO₄), creating a milky white solution in each test tube. Then, 10 drops of 6 M sodium hydroxide (NaOH) were added to the test tube containing BaSO₄, and 5 drops of 6 M NaOH were added to PbSO₄. The BaSO₄ did not dissolve in the NaOH, but the PbSO₄ did. The equations for lead’s reaction to nitric acid are as follows:

Table 3b. Summary of what happened after 1 drop of 6 M HNO₃ and various amounts of NaOH were added to lead (ii) and barium.

The reaction took place in two parts because the lead sulfate did not react with the nitric acid to directly make a new product. Rather, lead sulfate reacted with nitric acid to first make a new solid, then that solid reacted with the excess  ions to create an aqueous, clear solution of .

Lastly, 5 drops of 3 M sulfuric acid (H₂SO₄) was added to the clear solution of , causing the solution to turn warm and white, then partially release into the air as a stinky gas. In other words, the sulfuric acid caused an exothermic reaction.